P0402 Codes

[btfarm]

P0402 Excess EGR flow. I know it's old school now but I blocked and installed a Fingers Stick from Tony about 80k miles ago and had no codes for about 30k then started getting P0402s intermittently. If I look at the event data it's usually saying a command of around 105% max (amount over 100%). Sometimes only .5% over. Later I installed a downpipe back 4" Diamond Eye and since then it throws P0402 almost constantly. I've been over the FS wiring a couple of times and it's good and the truck runs as good as always. It's just annoying to have a MIL on all the time. Yeah I know... EFI.
But I'm satisfied with what I've been running for 100k with the Predator so I'm throwing the question out there. Am I missing something that causes the code? A faulty FS maybe? As far as I know the malfunction rate on the FS is like .0000001% so I doubt it but...?

 

[dmax711]

I would remove egr completly..Then get either ppe or efi to deal with the tuning.

 

[btfarm]

I don't have the $ to do a delete and EFI right now or it would already have been done but thanks. Just so you know, I was around DP with an LLY when Fingers invented it. I'm not exactly new to this.

 

[Fingers]

Assuming a good stick. Air leak between the MAF and the turbo or even an issue with the EGR valve. FS still requires a functional, if blocked, EGR valve.

 

[btfarm]

Thanks, is there anything I could look at internally to the FS? Of the other 2 thoughts, I'll carefully check around the MAF but that's always been good, the chance of the EGR motor malfunctioning would have likely failed entirely in the 80k it's showing the intermittant code I would think.

 

[Fingers]

Check the connection at the turbo and the PCV connection.

Nothing serviceable in the FS.

 

[btfarm]

Will do and thanks for checking in on this. Been a long time... Some of the old gang says hey!

 

[THEFERMANATOR]

Also check to make sure your intake resonator isn't cracked.

 

[btfarm]

I have a cap on it right now but I could put the resonator back on to see if it makes a difference. It didn't before but I don't remember when that was.

 

[THEFERMANATOR]

Make sure the cap hasn't come loose. If it can get air around there, it will code pretty quick.

 

[messejme]

The valve could be hanging in the open position due to debris or deterioration of the spring or rubber components.

 

[btfarm]

Cap clamp was a TAD loose. Everyting else good. I Put the resonator back on for now. We'll see how it goes. Slightly loose rubber cap could have been it I suppose. Kinda if that's it...